Assessment of Secondary Chemical and Mineralogical Trends at Lassen Volcano: Relevance to Early Mars Hydrothermalism Jordan C. Ludyan, Lindsay J. McHenry Department of Geosciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211
Introduction Objectives Water Analyses o Placing environmental and astrobiologic constraints on relict hydrothermal I. Observe how elemental makeup of substrate (andesite) affects how ions o Water analyzed at hot springs and fumaroles in this study reveal environments that are acidic, systems identified on Mars relies on our interpretation of geochemical reaction pathways partition into secondary mineral phases in acidic hydrothermal settings. mildly hot, and oxidizing observed in altered terrestrial materials. o The oxidizing conditions measured via Hydrolab are consistent with presence of significant II. Understand how oxidizing nature of Lassen geothermal waters/vapor o The Lassen hydrothermal system discharges volatiles from fumaroles that yield sulfate precipitates and lack of reduced mineral phases condensates impacts mineral diversity. acidic vapor condensates while acidic, oxidizing hot springs precipitate a variety of sulfate T pH ORP Cond. Salinity TDS minerals and alter substrate into residual silica and phyllosilicates. Hydrolab Results; Lassen 2016 III. Build upon existing framework for interpretation of proposed hydrothermal °C mV µS/cm psu g/L Murky, bubbling hot spring near Terminal 83.4 2.37 +508 9016 4.67 5.4 o Analysis of mineralogy and chemical enrichment/depletion trends combined with sites tentatively identified on the Martian surface through orbital and in-situ fumarole Geyser in-situ water sampling at hydrothermal sites allows us to place controls on the alteration measurement. Clear hot spring 91.4 3.81 +370 520 0.17 0.2 occurring as secondary mineral phases develop. Murky, bubbling hot spring 84.0 1.71 +576 19615 8.64 9.4 Pilot's Pinnacle Bubbling stream-flows through 33.4 2.21 +715 6884 3.16 3.8 hydrothermal area Geologic Context Pilot’s Pinnacle: XRF Results o Relative to substrate, L-16-PP-07, a yellow crust, is uniformly depleted in all Mars Hydrothermalism? o Lassen Volcano: largest hydrothermal system in the Cascades elements analyzed, though likely enriched in sulfur ➢ Discharges ~41kg/s steam—volcanic vapors and boiled meteoric water [1] Columbia Hills, Gusev Crater: o SiO and TiO insoluble in acidic settings—sulfur precipitation dilutes this o Volcanic materials range from andesite to dacite [2][3] 2 2 effect A. SiO2 and TiO2 enrichment in rocks and soils detected by Mars Exploration Rover (MER) Spirit at Home Plate [6]. Chemical/textural features favor biologically mediated sinter precipitation vs acid leaching [7] [8] o Vapor source at depth—boiled o L-16-PP-09, a beige altered clay, shows enrichment in SiO2, TiO2, Ba, Zr but is meteoric water undergoes phase- depleted in all other elements—typical of acid leached samples B. Variety of Fe-, Mg-, & Ca-sulfate minerals present in Paso Robles class soils near Home separation [1][4] Plate suggest precipitation from fumarolic condensates with lower water/rock ratios [9] C. ~0.5km from Home Plate—Carbonate-rich Comanche outcrop observed—neutral-pH ➢ Acidic volatile components(e.g. hydrothermal activity? [10] sulfur) fractionate into vapor phase and emerge as fumaroles Observations suggest diverse hydrothermal conditions ranging from hot and acidic to at higher elevations more neutral, potentially habitable environments ➢ Alkaline waters surface at lower A B C elevations as near-neutral, Cl-- rich hot springs
Isocon for sample diluted by sulfur L- Isocon highlighting 16-PP-07 enrichment/depletion trends for L- Field Sites 16-PP-09 relative to substrate Oct, 2016—Samples collected
in Lassen Volcanic National PHYLLOSILICATES PRIMARY Park SULFATES SMECTITES KAOLINS MINERALS
XRD (2:1) (1:1) PLAG
O
1
2
4 O
4 Implications
·22H2O
(Si
4
2
) 4
Results: (Si,Al)
O 2
O (OH)·22H 6 2
O
2 6
Fe 2
) (SO
O
4 2 4
O
2
O 2
0.3
2
(Al,Mg)
(OH)
6
· 11H · )Al 8
2 8
(SO o Alteration products at Lassen dominated by Al-
· 14H · 2
) H n ·
O
4
) O 3 2+
(OH) 4 2
0.33 2
O
) 4 3 2
· n H n · ,Na) 5
· 6 H 6 ·
3
3+
) 4
2
· 2 H 2 · 4
4
O Si
4 4
0.5
2 2
(SO
Fe
3
2
(OH) Si
(SO sulfates and Al-phyllosilicates
2+
2 2
10
)(OH)
Probably alunogen? Probably CaSO CaSO KFe KAL(SO MgSO Al(SO Al Fe (Mg,Fe TiO (Na,Ca) (CaO O Al (clay-mica) NaAlSi CaAl MgCaSi 0 ➢ Lassen andesites are high in Al (~16.8 wt. %) References ➢ Parent lithology significantly impacts alteration [1] Ingebritsen S.E. et al. (2016) Am. Mineral. 101, 343-353. products [2] Clynne M.A. (1999), Journal of Petrology. 40, 105-32.
[3] Clynne M.A. (2003). USGS Fact Sheet 101-
Amorphous Silica Tridymite Quartz Sulfur Sodium Alum Gypsum Anhydrite Jarosite Kalinite Hexahydrite Alunogen Meta alunogen Copiapite Pickeringite/Halo- trichite Anatase Montmorillonite Nontronite Kaolinite Illite Albite Anorthite Diopside Cristobalite o Martian basalts are high in Fe 02. Both Sites: Acid-Steam L-16-PP-02RIND X X X X X X X [4] McHenry L.J. et al. (2016) Am. Mineral. In ➢ Fe-sulfates and Fe-oxides detected near Home Press. Fumaroles & Steam-heated L-16-PP-02SUBSTRATE X X X X X X Plate, Gusev Crater [6] [11] [5] McHenry L.J. (2009) Chem. Geo. 265, 3-4. Acid Hot Springs L-16-PP-05 X X X X X [6] Squyres S.W. et al. (2008) Science. 320, 1063-1067. L-16-PP-06 X X [7] Ruff S.W. et al. (2011) JGR. 116, E00F23. L-16-PP-07 X X X X X X X X X o Smectites and kaolinite prominent in both sites—high [8] Ruff S.W. & Farmer J.D. (2016) Nat. L-16-PP-08 X X X X Commun. 7, 13554. PILOT'S PINNACLE PILOT'S W/R ratios in acidic settings Analytical Methods L-16-PP-09 X X X X X X [9] Yen A.S. et al. (2008) JGR. 113 (6), 1-19 L-16-TG-03 X X X X X [10] Morris R.V. (2010) Science. 329, 421-24 [11] Squyres S.W. (2006) JGR. 111 (2) o Mineralogy: Mineral and substrate samples were powdered by hand in a mortar and L-16-TG-04 X X X X X o So prominent near fumarole centers where samples pestle and analyzed using a Bruker D8 Focus X-Ray Diffractometer (XRD) [5]. L-16-TG-05 X X X X are in direct contact with acid-steam cloud L-16-TG-06 X X X X X X X Thanks to UWM’s Office of o Chemical composition: Dried samples were fused and analyzed using a Bruker S4 L-16-TG-07 X X X X Undergraduate Research and the Pioneer X-Ray Fluorescence (XRF) Spectrometer [5] for major, minor, and trace L-16-TG-08 X X X X o Mineralogical diversity increases near hot springs Wisconsin Space Grant Consortium for funding and NPS and Lassen Volcanic elements. L-16-TG-09 X X X X TERMINAL GEYSER TERMINAL L-16-TG-10 X X X X where sulfates precipitate directly from solution National Park for access. Also, thanks o In-situ water samples: Water samples were measured for T and pH in the field, and then L-16-TG-11 X X X X X to my mentor, Lindsay McHenry, and Andy Wanta and Ashley Stewart for further analyzed for total dissolved solids (TDS), oxidation-reduction potential (ORP), help with sample collection specific conductivity (Cond), and salinity using a Hydrolab sonde.